The animation is just a movement of position of the text layer under a matte.

The reason I need the text to be inserted for the bottom is so the content can be pulled in dynamically and the text fills the section from bottom up to start close to the green line at the bottom of the text frame.

AE text layers can be left, right or center justified. They can not be top, middle or bottom justified. It can be faked by moving the text layer's anchor point vertically, but it doesn't happen automatically.

You might be able to do that in other applications, but AE is not capable of it.

Yeah, it's annoying AE doesn't have this option in the paragraph palette.

A simple position expression on the text layer can fix the issue:

transform.position - [0, thisLayer.sourceRectAtTime().height-offset]

wherein "offset" is replaced by a number that keeps the textbox in its original place when the maximum number of text lines is filled with text, i.e. type the textbox full of text before figuring out what the offset amount is.